Functional neuroimaging of sex differences in autobiographical memory recall

Autobiographical memory (AM) is episodic memory for personally experienced events. The brain areas underlying AM retrieval are known to include several prefrontal cortical and medial temporal lobe regions. Sex differences in AM recall have been reported in several behavioral studies, but the functional anatomical correlates underlying such differences remain unclear. This study used fMRI to compare the neural correlates of AM recall between healthy male and female participants (n = 20 per group). AM recall in response to positive, negative, and neutral cue words was compared to a semantic memory task involving the generation of examples from a category using emotionally valenced cues. Behaviorally, females recalled more negative and fewer positive AMs compared with males, while ratings of arousal, vividness, and memory age did not differ significantly between sexes. Males and females also did not differ significantly in their performance on control tasks. Neurophysiologically, females showed increased hemodynamic activity compared to males in the dorsolateral prefrontal cortex (DLPFC), dorsal anterior insula, and precuneus while recalling specific AMs (all valences combined); increased activity in the DLPFC, transverse temporal gyrus, and precuneus while recalling positive AMs; and increased activity in the anterior cingulate cortex, precuneus, amygdala, and temporopolar cortex when recalling negative AMs. When comparing positive to negative AMs directly, males and females differed in their BOLD responses in the hippocampus and DLPFC. We propose that the differential hemodynamic changes may reflect sex-specific cognitive strategies during recall of AMs irrespective of the phenomenological properties of those memories.